Bitcoin dominance down, is this a good thing?

Looking at the bitcoin dominance it's down to 40% against an all time low of maybe about 36%? I forget the low.

But to me this seems like a bullish signal, a sign that your risk to reward in bitcoin is higher than eth or altcoins?

The alternative argument is that the weakening dominance is due to a weakening first mover effect and over takening by other coins.

But I don't think so? I think BTC has just been hammered more than other coins.

What do you all think?